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Zinc plating (Internal diameter)

 

Dear sir,

Which is the best alternative method for cyanide/chloride bath to achieve very good surface finish in the I.D of the pipe(7mm I.D to 13mm I.D)? Is there any other finishing available to avoid rust in the I.D of the pipe?

SOMASUNDARAM
- HOSUR, Tamil Nadu, India

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Getting zinc plating inside of a tube is hard, but it can be done. The challenge is getting a proper amount of electrical current down the tube. You should also consider electroless platings such as electroless nickel. The abbreviation EN is sometimes used in the industry to refer to this plating. This type of plating is driven by chemistry alone (not electrical current), and will plate the inside of your tubes.

Tim Neveau
Rochester Hills, Michigan
 

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Dear Mr Somu,

For your pipes I would advise you to go with Cyanide Zinc with a Medium Cyanide bath.

1.Its not easy to clean your pipes thoroughly and Cyanide Solns will do that for you and plate as well.

2.Medium Cyanide with a longer plating time will plate better thickness on the inside than a high Cyanide soln.

3. Acid Zinc will do none of the above and will give you variation of plating thickness, with very poor LCD to hCD area plating thickness.

4. You have not mentioned what anodes you're using. Quit using steel and switch to 99.99 % purity Zinc rods with a sludge free Cyanide Zinc solution if in case you're still using MS anodes.

Wish you all the best in your endeavours,

Khozem Vahaanwala
Saify Ind

Bengaluru, Karnataka, India